1957] 



BOTANY OF THE CHIMANTA MASSIF— I. 



407 



FIG. 77. Andropogon diutumus Sohns. a, pair of spikelets; b, sessile s pikelet; c, 

 first glume; d, second glume, e, cross section of first glume; /, cross section of second 

 glume; g, sterile lemma; h, fertile lemma; i, palea, lodicules, and essential organs; 

 palea and lodicules; k, two views of the ligule. a-h,-x 8; i-j, x 20 (type). 



8-10 mm long, behind the ligule on the basal blades, flat when green, drying 

 convolute, the midrib white and very prominent on the lower surface of mature 

 blades; racemes mostly one per peduncle, occasionally 2, mostly 4-5 cm long, 

 straight or slightly curved (not flexuous), densely white-hairy; rachis-joints 

 densely long-pilose from base to apex; sessile spikelet 4.1-6 mm long (excluding 

 the awn), their average length 5.2 mm (for 18 spikelets); first glume flat, sulcate, 

 glabrous, the tip slightly scabrous, often slightly bidentate; second glume as long 

 as the first, strongly-keeled, 3-nerved, the tip slightly scaberulous; sterile lemma 

 0.9-1.5 mm long, thin, transparent, appearing 2-keeled,the margins finely ciliolate; 

 fertile lemma thin, transparent, 3-nerved, bifid at the apex, awned from between 

 the lobes, the awn 7.5-14 mm long (measured from the tip of the first glume), the 

 column flat, twisted 3 or 4 times, brown, terminal portion pale, antrorsely scabrous; 

 palea a nerveless scale 1-2 mm long, often splitting at the tip; lodicules 2, 

 0.5-0.7 mm long, truncate, thickened at the top; stamens 3, the anthers yellow, 

 1-1.5 mm long; pistil well developed, the stigmas laterally exserted; pedicel about 

 1 mm shorter than the sessile spikelet, flattened, densely long-pilose on the 

 margins from base to apex; sterile spikelet 1.1-4.3 mm long (their average length 

 3 mm), reduced to the first glume and a rudiment (probably the second gJume). 



TYPE: locally frequent in small clumps; alt. 1925 m, vicinity of Summit Camp 

 along Ri'o Tirica, Central Section, Chimanta Massif, Estado Bolivar, Venezuela, 

 February 5, 1955, Julian A. Steyermark & John J. Wurdack 492 (US 2,182,125). 



